The Itajaí-Açu Formation (Portuguese: Formacão Itajaí-Açu) is a geological formation of the Santos Basin offshore of the Brazilian states of Rio de Janeiro, São Paulo, Paraná and Santa Catarina. The predominantly shale with interbedded turbiditic sandstones formation dates to the Late Cretaceous period; Cenomanian-Maastrichtian epochs and has a maximum thickness of 2,000 metres (6,600 ft). The formation is a reservoir rock of the fields in the Santos Basin.
| Itajaí-Açu Formation | |
|---|---|
| Stratigraphic range: Cenomanian-Maastrichtian ~ | |
| Type | Geological formation |
| Unit of | Frade Group |
| Underlies | Marambaia Formation |
| Overlies | Itanhaém Formation |
| Thickness | up to 2,000 m (6,600 ft) |
| Lithology | |
| Primary | Shale |
| Other | Sandstone |
| Location | |
| Coordinates | 26°6′S 43°43′W / 26.100°S 43.717°W |
| Region | Santos Basin, South Atlantic |
| Country |  Brazil |
| Type section | |
| Named for | Itajaí-Açu River |
 Location of the Santos Basin | |
Etymology
editThe formation is named after the Itajaí-Açu River, Santa Catarina.
Description
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The Itajaí-Açu Formation is 1,545 to 2,000 metres (5,069 to 6,562 ft) thick,[1] and comprises a thick interval of dark grey clayey rocks, interbedded with the clastics of the Santos and Juréia Formations. Within this formation, the Ilhabela Member includes the turbiditic sandstones occurring along the section. The sedimentary environment is thought to be marine talus to open basin. Biostratigraphic data from palynomorphs, calcareous nannofossils and planktonic foraminifera indicate a Late Cretaceous age (Cenomanian-Maastrichtian).[2]
Petroleum geology
editThe formation, mainly its Ilhabela Member, is the main post-salt reservoir rock of the Santos Basin.[3][4] The formation also is the main post-salt source rock and a seal for the post-salt reservoirs.[5]
Fields with Itajaí-Açu reservoirs
edit| Field | Year | Operator | Reserves (in place) | Notes |
|---|---|---|---|---|
| Panoramix | 2009 | Repsol | 176 million bbl (28.0 million m3) | |
| Piracucá | 2009 | Petrobras | 321.4 million bbl (51.1 million m3) | |
| Cedro | 2005 | Petrobras | 95.76 million bbl (15.2 million m3) | |
| Lagosta | 2003 | El Paso Corp. | 0.173 trillion cu ft (4.9 billion m3) | |
| Uruguá | 2003 | Petrobras | 174.27 million bbl (27.7 million m3) 1 trillion cu ft (28 billion m3) |
|
| Carapiá | 2002 | Petrobras | 63.52 million bbl (10.1 million m3) | |
| Mexilhão | 2001 | Petrobras | 532.23 million bbl (84.6 million m3) 3.4 trillion cu ft (96 billion m3) |
|
| Tambuatá | 1999 | Petrobras | 212.8 million bbl (33.8 million m3) |
See also
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References
edit- ^ Kiang Chang et al., 2008, p.32
- ^ Clemente, 2013, p.23
- ^ a b c d e f g h i "Santos Basin Fields". Archived from the original on 2017-09-07. Retrieved 2017-09-07.
- ^ Juarez, 2013, p.7
- ^ Contreras, 2011, p.77
- ^ Piracucá Field
- ^ Petrobras BS-400 gas find confirms E&P expansion plans
- ^ a b c Vieira, 2007, p.9
- ^ a b Juarez, 2013, p.14
- ^ Vieira, 2007, p.8
Bibliography
edit- Clemente, Pilar (2013), Petroleum geology of the Campos and Santos basins, Lower Cretaceous Brazilian sector of the South Atlantic margin, Danmarks Tekniske Universitet, pp. 1–33, retrieved 2017-09-04
- Contreras, Jorham (2011), Seismo-stratigraphy and numerical basin modeling of the southern Brazilian continental margin (Campos, Santos, and Pelotas basins) (PhD thesis) (PDF), Ruprecht-Karls-Universität Heidelberg, pp. 1–171, retrieved 2017-09-04
- Juarez Feijó, Fávio (2013), "Santos Basin: 40 Years from Shallow to Deep to Ultra-Deep Water" (PDF), Search and Discovery, 10553: 1–49, retrieved 2017-09-04
- Kiang Chang, Hung; Assine, Mario Luis; Santos Corrêa, Fernando; Setsuo Tinen, Julio; Campane Vidal, Alexandre; Koike, Luzia (2008), "Sistemas petrolíferos e modelos de acumulação de hidrocarbonetos na Bacia de Santos" (PDF), Revista Brasileira de Geociências, 38: 29–46, doi:10.25249/0375-7536.2008382S2946 (inactive 1 November 2024), retrieved 2017-09-04
{{citation}}: CS1 maint: DOI inactive as of November 2024 (link) - Vieira, Juliana (2007), Brazil Round 9 - Santos Basin (PDF), ANP, pp. 1–73, archived from the original (PDF) on 2017-02-03, retrieved 2017-09-04